Problem: Simplify the following expression: $x = \dfrac{3}{6z + 5} \div \dfrac{4}{4z}$
Dividing by an expression is the same as multiplying by its inverse. $x = \dfrac{3}{6z + 5} \times \dfrac{4z}{4}$ When multiplying fractions, we multiply the numerators and the denominators. $x = \dfrac{ 3 \times 4z } { (6z + 5) \times 4}$ $x = \dfrac{12z}{24z + 20}$ Simplify: $x = \dfrac{3z}{6z + 5}$